U.S. Pat. No. 6,104,297 discloses a corona discharge detection system for detecting a defect in a high voltage cable, transformer or other piece of high voltage equipment. An optical sensor generates an electrical signal in response to the detection of ultraviolet radiation in a prescribed range from a discharge. The sensor is selected for discrimination of the sensed ultraviolet from sun radiation.
U.S. Pat. No. 6,476,396 discloses an electro-optical, non-contact measurement of electrical discharges. Optical filtering is used to pass selected wavelengths of ultraviolet, visible or near-infrared light from a discharge to a light-collecting optical detector with high sensitivity at the selected wavelengths. A signal processor analyzes the output of the optical detector with a matched filter technique or a pulse-height analyzer.
An arc discharge may occur internally within a high voltage power supply, or in an external component (such as a cable or x-ray tube) electrically connected to the power supply. The above prior art may be used to detect and locate an arc discharge, but is not capable of determining whether the discharge occurred within a high voltage power supply, or an external component, when the arc discharge sensor is provided within the power supply. Consequently, if the discharge occurs in an external component connected to the power supply, a technician who is troubleshooting the source of the arc may replace one or more power supplies before he or she realizes that the arc is occurring in the external component. Therefore there is the need for a corona discharge detector with a sensor disposed within a high voltage power supply, or other high voltage component, that will sense whether the corona discharge (arcing) has occurred internally in the high voltage component or in an external component electrically connected to the high voltage component.